What is termed Optical Burst Switching (OBS) will be employed for transmitting data over future optical networks. This entails combining a plurality of data packets into what are termed data bursts and then transmitting them over a data channel in the optical network. Each data channel corresponds to a specific wavelength of a wavelength multiplex signal having a multiplicity of said channels over which data signals are transmitted simultaneously. Different messages from different sources can be transmitted over each data channel. There will be longer delays in the sending of data bursts when the traffic volume is higher because fewer free timeslots will be available for transmitting them. Optimal utilization of the available transmission capacity, and hence a reduced probability of blocking, is a major aim in said networks. The probability of blocking is reduced by a “Two-Way-Reservation OBS Network” (2WR OBS) in which a reservation request is sent by the sending network node and the acknowledgement that the connection path is free is sent by a receiving network node.
In what is termed λ switching, where a plurality of wavelengths (channels) are available, the switching granularity is a wavelength. An entire transmission channel will consequently be occupied even when the traffic volume is low. So this method is not optimal, either.